This invention pertains to improvements in loose-leaf binders. More particularly, this invention pertains to improvements in loose-leaf binders of the type employing a plurality of aligned ring-pairs mounted to elongated, resilient hookplates retained by a curved coverplate. The hookplates are pivotable along the longitudinal axis defined by the outer edges of each plate. The inner edges of the plates are joined in a hinged relationship such that the plates are positionable in an inwardly bowed orientation toward the coverplate and an outwardly bowed orientation away from the coverplate. In these respective positions, the binder rings which are mounted to the hookplates are accordingly in an open or closed orientation.
It is desirable to provide means for reliably locking binder rings in the closed position to avoid accidental opening and possible damage to or loss of materials stored in the binder. Various forms of locking apparatus have been incorporated in loose-leaf binder mechanisms, as described in U.S. Pat. Nos. 2,061,676, 2,105,235, 2,950,719, 3,077,888, 3,098,490, 3,884,586 and 4,566,817. These prior art devices are generally effective in providing binder locking capability, however all are constructed of more than one component and require several assembly operations to manufacture.
It may be desirable to provide means for suspending a binder in an inverted orientation from a file-frame unit such as a Pendaflex.RTM. system. (Pendaflex is a registered trademark of Esselte Pendaflex Corp.). Past efforts in providing this capability have generally utilized two basic approaches: the first approach has been to provide an extendable arm at each end of the binder. The arm generally has been mounted in channels or tracks attached to or constructed as part of the coverplate. The second approach has been to provide permanently mounted tabs which extend from each end of the binder. This second approach has the significant drawback of preventing the storage of the binder on a shelf in an upright position, such as a book is stored on a library shelf. Both approaches are characterized by the requirement for several components, adding to the cost and complexity of manufacturing the binder mechanism.
It will be appreciated that when the binder is suspended in an inverted orientation the resulting weight of the materials upon the binder rings almost always mandates that some type of lock is utilized to secure the rings in the closed position.
It is with these considerations that the present invention was developed. The primary object is to provide a reliable binder locking means which also functions as a rigid file-frame hanger. The hanger is fully retractable to allow the binder to also be stored in an upright position on a shelf.
Another object of the present invention is to provide a dual-function binder mechanism locking and hanging capability with a single component which is readily formed, low in cost, and extremely easy to manufacture.
A related object of the present invention is to provide through the use of the same mass-producible component, means for producing a low-cost, reliable, locking binder mechanism for applications which do not require the capability for file-frame storage.